Welding and Foundry Technology MCQs 2026

Heat-affected zone (HAZ) is

1. A only weld metal deposit ✓
2. B only shielding gas envelope ✓
3. C only flux granules ✓
4. D base metal region whose microstructure changed from welding heat ✓

Preheat in welding reduces

1. A always increases hardness cracking risk without exception ✓
2. B only electrode cost ✓
3. C only arc length ✓
4. D cooling rate and hydrogen cracking susceptibility ✓

Hydrogen-induced cracking (cold cracking) is influenced by

1. A only paint colour ✓
2. B only wind speed outdoors only on MIG always ✓
3. C hydrogen, susceptible microstructure and restraint stress ✓
4. D only electrode diameter decorative ✓

Crater crack forms at

1. A start of weld only always ✓
2. B stop crater where shrinkage concentrates ✓
3. C only parent metal 100 mm away ✓
4. D only flux bucket ✓

Slag inclusion in weld results from

1. A trapped flux or slag not removed between passes ✓
2. B only shielding gas argon ✓
3. C only tungsten tip ✓
4. D only preheat temperature alone ✓

Lack of fusion (cold lap) means

1. A weld metal not fused properly with base or previous pass ✓
2. B perfect bonding always ✓
3. C only excessive reinforcement ✓
4. D only slag inclusion beneficial ✓

Undercut is a groove melted into

1. A centre of weld bead only convex ✓
2. B base metal at toe of weld leaving notch ✓
3. C only heat affected zone far away ✓
4. D only flux coating ✓

Welding defect porosity is

1. A only surface colour change ✓
2. B only excessive penetration beneficially ✓
3. C gas pockets trapped in weld metal ✓
4. D only parent metal hardness ✓

DCEP in SMAW often used for

1. A always decreases penetration without exception all rods ✓
2. B only aluminium TIG always ✓
3. C only submerged arc ✓
4. D certain electrodes requiring more heat in electrode ✓

Polarity DCEN in GTAW means

1. A electrode positive always shallow only ✓
2. B alternating only ✓
3. C no current flow ✓
4. D electrode negative, deeper penetration into work ✓

Welding transformer or inverter power source provides

1. A only compressed air for brakes ✓
2. B only hydraulic oil pressure ✓
3. C controlled current/voltage for arc stability ✓
4. D only diesel torque ✓

Resistance spot welding joins sheet metal by

1. A only ultrasonic vibration without current ✓
2. B passing current through contact points creating heat ✓
3. C only bolt tension ✓
4. D only adhesive ✓

Oxy-acetylene welding flame neutral balance is used for

1. A welding and cutting steels with balanced combustion ✓
2. B only carburizing always without oxygen adjustment ✓
3. C only oxidizing always ✓
4. D only water cooling ✓

Submerged arc welding (SAW) features

1. A arc hidden under granular flux blanket ✓
2. B open arc without flux ✓
3. C only manual stick outdoors in wind ✓
4. D only plastic joint ✓

Weld symbol on drawing arrow side means

1. A always opposite side only ✓
2. B only both sides without symbol ✓
3. C weld on side arrow points to ✓
4. D only no weld ✓

Fillet weld leg size refers to

1. A only throat depth without legs ✓
2. B distance from root to face along leg in right triangle approximation ✓
3. C only groove angle only ✓
4. D only electrode brand ✓

Butt weld groove types include

1. A V, U, J and square grooves ✓
2. B only spot only always ✓
3. C only seam adhesive ✓
4. D only rivet heads ✓

Backing strip or backing gas prevents

1. A incomplete root penetration or oxidation at root ✓
2. B only cosmetic spatter increase deliberately ✓
3. C only electrode melting ✓
4. D only shield gas tank colour ✓

WPS stands for

1. A Wire Power Supply ✓
2. B Welding Procedure Specification ✓
3. C Weld Profile Standard ✓
4. D Water Preheat System ✓

Welder qualification certifies

1. A only engineering degree ✓
2. B only crane license ✓
3. C only boiler operator ✓
4. D welder skill for positions and processes ✓

Foundry process casting pours

1. A only removes metal by machining exclusively ✓
2. B only joins by bolts ✓
3. C only extrudes polymer ✓
4. D molten metal into mould cavity to solidify ✓

Pattern in foundry is

1. A only cutting tool for lathe ✓
2. B only welding electrode ✓
3. C replica of casting used to form mould cavity ✓
4. D only hydraulic seal ✓

Moulding sand properties include

1. A only electrical conductivity high ✓
2. B permeability, cohesiveness, refractoriness and collapsibility ✓
3. C only transparency ✓
4. D only magnetic permeability high always ✓

Core in foundry creates

1. A internal cavities in casting ✓
2. B only external riser ✓
3. C only gating sprue exclusively external ✓
4. D only pattern draft angle ✓

Riser feeds

1. A liquid metal to compensate solidification shrinkage ✓
2. B only slag to mould ✓
3. C only air to cavity ✓
4. D only coolant water to core ✓

Gating system includes

1. A only machining fixtures ✓
2. B pouring cup, sprue, runner and gates ✓
3. C only welding leads ✓
4. D only inspection gauge blocks ✓

Chill in mould promotes

1. A only slower solidification everywhere ✓
2. B only gas porosity deliberately ✓
3. C directional solidification and fine grain at surface ✓
4. D only sand fusion only ✓

Casting defect misrun is

1. A excess metal flash only ✓
2. B only intentional hole ✓
3. C only perfect casting ✓
4. D incomplete filling of mould cavity ✓

Shrinkage cavity in casting is

1. A only surface oxide only ✓
2. B only core shift only without void ✓
3. C only machining chip ✓
4. D void from insufficient feeding during solidification ✓

Hot tearing (hot cracking) in casting occurs

1. A only at room temperature years later only ✓
2. B only in liquid metal before pour ✓
3. C during solidification with restraint ✓
4. D only in mould sand ✓

Sand casting is

1. A only permanent die without sand ever ✓
2. B most versatile casting using expendable sand mould ✓
3. C only investment for tiny parts only always ✓
4. D only continuous casting billet ✓

Investment casting uses

1. A wax pattern coated with ceramic shell then melted out ✓
2. B only dry sand without coating ✓
3. C only wooden pattern without shell ✓
4. D only welded plate fabrication ✓

Die casting forces molten metal into

1. A metal die under high pressure ✓
2. B only sand mould by gravity alone ✓
3. C only plaster without pressure ✓
4. D only forge hammer ✓

Centrifugal casting produces

1. A only flat sheet ✓
2. B hollow cylindrical parts by rotating mould ✓
3. C only powder compact ✓
4. D only welded pipe seam ✓

Continuous casting makes

1. A only single jewellery piece ✓
2. B only sand mould one-off ✓
3. C billets, blooms, slabs by ongoing solidification ✓
4. D only wooden beam ✓

Fettling in foundry means

1. A only pouring metal ✓
2. B only melting scrap only ✓
3. C only pattern making only ✓
4. D removing gates, risers and flash from casting ✓

Permeability of sand allows

1. A only blocks all gas causing blows ✓
2. B only increases moisture always bad without balance ✓
3. C only hardens core irreversibly only ✓
4. D escape of gases during pouring ✓

Cohesiveness (green strength) of sand mould

1. A only dissolves instantly in water always before pour ✓
2. B only conducts electricity ✓
3. C holds shape until metal poured ✓
4. D only repels all moisture ✓

Collapsibility of mould sand allows

1. A permanent rigid mould always ✓
2. B easy shakeout without cracking casting during contraction ✓
3. C only increases casting stress during cooling ✓
4. D only welds casting to sand ✓

Eutectic in cast iron near 4.3% C gives

1. A lowest melting mixture for good fluidity in hypoeutectic alloys context ✓
2. B only martensite plates ✓
3. C only gas holes always ✓
4. D only pure copper ✓

MIG welding uses

1. A only tungsten non-consumable ✓
2. B consumable wire electrode and shielding gas ✓
3. C only forge hammer ✓
4. D only rivets ✓

Pakistan welding standards reference

1. A only woodworking joints exclusively ✓
2. B only textile stitching ✓
3. C only food recipes ✓
4. D international codes AWS, ASME and local industry practice ✓

Electron beam welding requires

1. A only open air without vacuum always ✓
2. B only water tank ✓
3. C vacuum chamber to prevent beam scatter ✓
4. D only sand mould ✓

Laser beam welding offers

1. A only widest HAZ always ✓
2. B concentrated heat narrow HAZ high depth-to-width ratio ✓
3. C only cannot automate ✓
4. D only for plastics exclusively ✓

Friction stir welding is

1. A solid-state joining using rotating tool friction heat ✓
2. B only oxy cutting ✓
3. C only submerged arc with wire ✓
4. D only resistance spot only ✓

Forge welding historically

1. A joins heated metals by hammering together ✓
2. B only arc with electrode ✓
3. C only adhesive epoxy ✓
4. D only laser cutting ✓

Soldering uses filler melting below

1. A 2000°C ✓
2. B 450°C (traditionally) ✓
3. C base metal melting point always ✓
4. D only solid state without filler ✓

Brazing joins metals using

1. A fusion of base metal only like welding without filler ✓
2. B only mechanical rivets ✓
3. C filler melted above 450°C but below base metal melting ✓
4. D only cold welding without heat ✓

Post-weld heat treatment may

1. A only quench to martensite always all steels ✓
2. B only paint immediately without need ✓
3. C only increase hydrogen ✓
4. D stress relieve or temper hard HAZ ✓

Peening after welding can

1. A only increase tensile stress deliberately all zones ✓
2. B only remove weld metal ✓
3. C only increase hydrogen ✓
4. D relieve tensile residual stresses by plastic deformation ✓

Distortion in welding is reduced by

1. A only maximum heat input always ✓
2. B only single long bead without restraint ✓
3. C tack welding, sequencing, fixturing and intermittent welds ✓
4. D only increasing gap unlimited ✓

Welding stainless steel often requires

1. A only mild steel electrodes always without spec ✓
2. B low carbon grades and proper shielding to prevent sensitization ✓
3. C only oxy-fuel without control ✓
4. D only no gas TIG outdoors wind ✓

Nodularity in ductile iron from

1. A magnesium treatment spheroidizing graphite ✓
2. B only rapid quench martensite ✓
3. C only sulphur addition always flakes ✓
4. D only zinc coating ✓

GTAW is commonly called

1. A MIG only ✓
2. B Stick only ✓
3. C SAW only ✓
4. D TIG welding ✓

GMAW is commonly called

1. A TIG only ✓
2. B Submerged arc only ✓
3. C Oxy-fuel only ✓
4. D MIG/MAG welding ✓

Arc welding uses

1. A only cold pressure without heat ✓
2. B electric arc as heat source between electrode and work ✓
3. C only laser without electricity ever ✓
4. D only adhesive bond ✓

Welding is a process of

1. A joining metals by fusion with or without filler and pressure ✓
2. B only mechanical bolting without bond ✓
3. C only painting surfaces ✓
4. D only casting molten metal into mould only without joint ✓